Niesen becomes the second Duck to be signed by a Major League organization in the past week, following Ben Broussard, who was signed by Kansas City on July 4.

“Eric has done a tremendous job for the Ducks and we’re pleased to see him get this opportunity,” says Ducks President/GM Michael Pfaff. “We wish him the best of luck with the Red Sox organization.”

Niesen will report to Triple-A Pawtucket of the International League for Tuesday's Pawsox game at Lehigh Valley - his first Triple A experience. While with the Ducks, the lefthander posted a 4-0 record with 3.23 ERA.

He struck out 39 batters in 39 innings while allowing 34 hits.

Injuries to Andrew Miller and Franklin Morales have left Craig Breslow as Boston's only left-hander in the bullpen.